Electrolytic brush assembly

ABSTRACT

Disclosed herein is an electrolytic brush assembly comprising a handle assembly; a shroud extending from the handle assembly, the shroud having an aperture at a distal end thereof; a brush connecting assembly for releasably connecting a brush to the handle assembly whereby the brush extends through the aperture of the shroud and a fluid delivery assembly. The handle assembly comprises an adjustment sub-assembly for selectively moving the brush connecting assembly and a brush connected thereto relative to the handle assembly and the aperture of the shroud. The fluid delivery assembly delivers electrolytic fluid to the proximity of the brush, optionally under closed loop control.

TECHNICAL FIELD

The present invention relates generally to electrolytic cleaning ofmetals, and more particularly to a conductive brush assembly used inelectrolytic cleaning of metal welds.

BACKGROUND TO THE INVENTION

During the process of welding a metal, it is common for the metal tobecome discoloured by the welding process. For example, when weldingstainless steel, the chromium content of the metal is depleted, exposingiron and causing a localised discolouration of the stainless steel,known as “heat tint”. In other applications, oxides form during thewelding process, leaving unattractive deposits on the surface of themetal, or otherwise discolouring the metal.

It is common practice that after a metal has been welded, thediscoloured surfaces are cleaned to remove or reduce the heat tint. Inthe past, this has typically been performed by a variety of methods,such as using an abrasive, bead blasting or exposing the discolouredregion to strong acids.

More recently, cleaning of welded joints has been performed using anelectrically charged pad or brush applicator having conductivefilaments, in conjunction with an electrolyte, to clean a metal surfaceby applying a concurrent chemical reaction, heat and electric current.The simultaneous electrolytic and high temperature cleaning action hasproven successful in efficient cleaning of welded metals, particularlyin cleaning stainless steel. Known electrically charged brushes havingconductive filaments can, however, suffer from a number of drawbacks.For example, known brushes can perform poorly because their relativelylong filaments tend to flop on their sides, particularly when wet withelectrolyte, rather than presenting erect filament ends as the workingcontact point. Applying the electrolyte to a weld with the filaments cantherefore be somewhat haphazard, which is problematic because theelectrolyte is typically highly acidic and spillage likely to causedamage.

The conductive brush for cleaning welded stainless steel disclosed ininternational PCT publication WO 2010/085849 was developed to addresssuch a drawback. The brush disclosed in this patent application has abody connected to a fixed length of conductive brush filaments and asheath arranged around the filaments. The sheath has an aperture throughwhich the filaments extend having a profile of a particular geometry toshape the filaments retained within the sheath. The sheath is alsomovable with respect to the body and filaments, the movement adjustingthe portion of brush filaments that protrude from the aperture, therebyadjusting the effective length and stiffness of the filaments.

Whilst the brush disclosed in WO 2010/085849 has various advantages overearlier brushes (e.g. as noted above), it also has a number ofdrawbacks. For example, the position of the sheath with respect to thefilaments or body is freely adjustable and is unable to be locked.During use, this requires a user to manually maintain the position ofthe sheath or else the sheath may move from the desired position (e.g.when accidentally knocked whilst cleaning a weld, as can often happen),thereby adjusting the effective length and stiffness of the filaments.Such a requirement typically necessitates a two handed operation which,in addition to the cleaning manipulations, can make the brush veryunergonomic to handle.

Additionally, known prior art brush systems and pad systems lackeffective automatic control of the delivery of electrolytic fluid to theapplicator. Such lack of control can result in the opposite extremes offluid delivery; either excess fluid which creates a messy and dangerouswork environment with high fluid costs, or a paucity of fluid whichcreates surface burning, decreased cleaning effectiveness and prematurefailure. Currently, the operator must “guess” the amount of electrolyticfluid to supply to the applicator, either via manual dipping or bysetting a fluid delivery control that is effectively “open loop.”

The only proposed method of automatic fluid supply known to theinventors in the prior art is that claimed in U.S. Pat. No. 8,813,301 B2“Conductive Brush for cleaning metals.” This method relies on theobvious practice of supplying fluid to a brush head via the intersticesformed between the brush fibres where they are clamped into a bundle.Experiments performed by the inventors have shown this method tocommonly result in the unwanted and uncontrolled restriction of fluidflow due to both the variability in clamping force on the fibres and therapid build up of clogging material in the narrow interstices,

A need exists for a conductive brush assembly which overcomes, or atleast ameliorates, one or more of the disadvantages of the prior artarrangements.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided anelectrolytic brush assembly comprising:

a handle assembly;a shroud extending from the handle assembly, the shroud having anaperture at a distal end thereof; anda brush connecting assembly for releasably connecting a brush to thehandle assembly whereby the brush extends through the aperture of theshroud,wherein the handle assembly comprises an adjustment sub-assembly forselectively moving the brush connecting assembly and a brush connectedthereto relative to the handle assembly and the aperture of the shroud.

According to a second aspect of the invention, there is provided anelectrolytic brush assembly comprising:

a handle assembly;a shroud extending from the handle assembly, the shroud having anaperture at a distal end thereof; anda brush releasably connected to the handle assembly and extendingthrough the aperture of the shroud,wherein the handle assembly comprises an adjustment sub-assembly forselectively moving the brush relative to the handle assembly and theaperture of the shroud.

According to a third aspect of the invention there is provided a fluidcontrol and delivery assembly in communication with the brush for thesupply of electrolytic fluid to the brush comprising:

an input connection for the reception of electrolytic fluid from a storeor reservoir;a tube or other means of delivering said fluid to the brush fibres;a pump or other transfer means for driving said fluid into the proximityof the brush fibres; anda fluid control means for regulating the flow through said pump or othertransfer means wherein the magnitude of the flow is determined by thereception from sensing means of parameter values which may vary with thequantity of electrolytic fluid present in the brush;

Embodiments of the second and third aspects of the invention may be thesame as the embodiments of the first aspect of the invention, asdescribed herein.

Other aspects are also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will now be described, byway of example only, with reference to the accompanying drawings inwhich:

FIG. 1 is a perspective view of an electrolytic brush assembly inaccordance with an embodiment of the present invention;

FIG. 2 is a cut-away side view of the brush assembly shown in FIG. 1;

FIG. 3 is a detailed view of the brush of the brush assembly shown inFIGS. 1 and 2;

FIG. 4 is an exploded view of an alternative embodiment of a brushconnecting assembly in accordance with an embodiment of the presentinvention; and

FIG. 5 is a view of the brush connecting assembly of FIG. 4 in anassembled state.

FIG. 6 is an exploded view of the shroud assembly, illustrating anembodiment of the associated electrolytic fluid delivery conduit.

FIG. 7 is a cross sectional view of the shroud assembly, illustrating anembodiment of an integral electrolytic fluid delivery conduit.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As noted above, the present invention relates to an electrolytic brushassembly. In its first aspect, the electrolytic brush assembly comprisesa handle assembly; a shroud extending from the handle assembly, theshroud having an aperture at a distal end thereof; a brush connectingassembly for releasably connecting a brush to the handle assembly suchthat the brush extends through the aperture of the shroud; anelectrolytic fluid delivery conduit, communicating between an externalfluid reservoir (not shown) and the brush; and a fluid control meansthat regulates and delivers the flow of said fluid to the brush. Thehandle assembly comprises an adjustment sub-assembly for selectivelymoving the brush connecting assembly and a brush connected theretorelative to the handle assembly and the aperture of the shroud.

In its second aspect, the electrolytic brush assembly comprises a handleassembly; a shroud extending from the handle assembly, the shroud havingan aperture at a distal end thereof; a brush releasably connected to thehandle assembly and extending through the aperture of the shroud; and anelectrolytic fluid delivery conduit, communicating between an externalfluid reservoir (not shown) and the brush; and a fluid control meansthat regulates the flow of said fluid to the brush. The handle assemblycomprises an adjustment sub-assembly for selectively moving the brushrelative to the handle assembly and the aperture of the shroud.

The electrolytic brush assemblies of the present inventionadvantageously use a brush which is both releasably connectable to theassembly and selectively moveable in order to control the amount of thebrush which extends through the shroud's aperture. Providing anelectrolytic brush assembly in which the brush is replaceable isadvantageous because brushes tend to wear out with use and, in manyprior art electrically charged brushes, the brushes are either notreplaceable, or are replaceable but necessitate that the electricallycharged brushes be switched off and cleaned to remove any causticelectrolytic cleaning chemicals beforehand.

Providing an lectrolytic brush assembly in which the brush isselectively moveable in order to control the amount of the brush whichextends through the shroud's aperture is advantageous because the brushmay be moved (relative to the handle assembly and aperture of theshroud) such that the proportion of the brush's filaments extendingthrough the shroud's aperture can be selectively adjusted (e.g. by auser or automatically) based on factors such as wear on the brush andthe relative stiffness of the brush's exposed filaments. Furthermore,accidentally striking the shroud during use of the electrolytic brushassembly will not cause it to move and thus affect the shape of thebrush. As noted above, this can be a problem of existing conductivebrushes.

Actuating the adjustment sub-assembly need not be a two-handed operationand may, in some embodiments, be conducted whilst the electronic brushassembly is in use. The adjustment sub-assembly may, in someembodiments, be quickly and easily actuated in order to fine tune theperformance of the brush in response to a particular application (e.g.the brush can be extended if a weld requiring cleaning is in a hard toreach position). Further, when performing such adjustments it is notnecessary for a user to touch (or risk inadvertently touching) the hotand caustic brush filaments.

The electrolytic brush assemblies of the present invention comprise ahandle assembly. The handle assembly may have any form, as long as itcan be held in the hand of an operator (preferably one hand only) andprovide the functions recited herein.

The electrolytic brush assembly of the present invention may be moreergonomic to use than existing electrically charged brushes. Manyexisting electrically charged brushes are similar to paint brushes, werethe user's wrist needs to be bent in order to clean the welds.Typically, the electrolytic brush assembly of the present invention willbe ergonomically designed for ease of operation by a user and to lessenthe risk of injury by overuse. In some embodiments, the handle assemblymay therefore include grips such as a pistol grip handle, for example,which can help to make the assembly easier for the user to operate. Theelectrolytic brush assembly of the present invention may, for example,be provided in the form of a T-shape, with the brush and the handlebeing at right angles to each other, such that a user's wrist issubstantially in line with their arm when operating the brush.

Furthermore, in some embodiments of the present invention (some of whichare described in further detail below), it may be necessary for conduitsto pass through the electrolytic brush assembly (e.g. to carry inelectrolytic cleaning fluid or carry out potentially toxic fumes). Insuch embodiments, running these tubes through a pistol grip handle (orother gripable handle) would provide a more suitable weight balance inthe brush, again making it more ergonomic for the user.

The handle assembly comprises an adjustment sub-assembly for selectivelymoving the brush connecting assembly and/or brush relative to the handleassembly and the aperture of the shroud.

The adjustment sub-assembly may include any suitable components,provided that they are operable to selectively move the brush in themanner described herein. In some embodiments, for example, theadjustment sub-assembly comprises a sheath; a rod slidably receivedwithin the sheath, the rod being connected to the brush connectingassembly; and an actuator for moving the rod within the sheath.Actuating the rod causes the brush connecting assembly and/or brush tomove relative to the handle assembly and the aperture of the shroud.

The actuator in the adjustment sub-assembly may include any suitablecomponents, provided again that they achieve the function describedherein. In some embodiments, for example, the actuator comprises arotatable sleeve having an inner thread functionally connected to therod. Rotation of the rotatable sleeve causes linear movement of the rodwithin the sheath. As noted above, such linear movement causes the brushconnecting assembly and/or brush to move relative to the handle assemblyand the aperture of the shroud.

The actuator may be actuated either manually (e.g. by a user rotatingthe sleeve when they want to expose more of the brush's filaments toprovide extra reach or a softer tip, or retract the brush to provide afirmer tip) or automatically (e.g. in response to the length of theexposed brush falling below a predetermined amount).

The electrolytic brush assembly of the present invention also comprisesa shroud extending from the handle assembly. The shroud has an apertureat a distal end thereof, through which the end of any brush releasablyconnected to the handle assembly, such that it can be applied to awelded surface in order to clean the weld.

The shroud may have any form, provided that it is suitable for use withthe electrolytic brush assembly described herein. Typically, the shroudwill be shaped such that it can comfortably house the brush and anyother components of the assembly intended to be received therein. Theshroud may contain openings such that any fumes etc. that may form andheat generated by the electrical connections can dissipate into theenvironment. Alternatively, the shroud may contain no openings (i.e.except the aperture), such that fumes can be extracted and remotelydisposed (as described below) and/or cleaning fluids can be pumped intothe shroud and hence on to the brush filaments (as described below).

The aperture of the shroud (i.e. through which the brush extends) mayhave any suitable shape. As will be appreciated, the shape of theshroud's aperture will affect the pattern which the brush filamentsmake. Typically, the aperture will be circular or rectangular, althoughother shapes may be advantageous ib some circumstances.

Typically, the shroud is fixed with respect to the handle assembly sothat it cannot be moved, even in the event of it being struck duringoperation of the electrolytic brush assembly. Typically, the shroudencloses a volume surrounding the non-exposed portion of the brush, withconditions within the volume being monitorable (as discussed below) inorder to better control the operation of the electrolytic brushassembly.

In some embodiments, for example, a volume defined by the shroud may befluidly connected to conduits (e.g. in the handle assembly), wherein theconduits are fluidly connectable to an external extraction pump, therebyallowing fumes created within the volume to be extracted duringoperation.

In some embodiments, for example, the fluid delivery means may becontained in or associated with the shroud thereby allowing electrolyticcleaning fluid to be continuously delivered (as needed) to the filamentsof the brush via the fluid control means. Such a continuous delivery ofcleaning fluid represents a significant improvement over existingelectrically charged brushes, which require the brush to be regularlydipped into a container of the cleaning fluid. The fluid may becontinuously delivered via these conduits, or delivered only upon demandby the user (e.g. by squeezing a trigger on the pistol grip handle).

In the electrolytic brush assembly of the present invention, the brushis either releasably connectable to the handle assembly via a brushconnecting assembly, or is provided releasably connected to the handleassembly. As noted above, releasably connecting the brush to theassembly enables the brush to be easily replaced at the end of itsuseful life.

The brush may be releasably connectable to the brush connecting assemblyby any suitable mechanism. Typically, the brush is releasablyconnectable to the brush connecting assembly by a quick releasemechanism, which enables a spent brush to be quickly and easilydisconnected and a new brush to be quickly and easily connected.Typically, such disconnection would not necessitate a user handling thebrush, as it will likely be hot and/or contaminated with potentiallycorrosive chemicals such as acids.

In some embodiments, for example, the quick release mechanism maycomprise a female quick-connect coupler for receiving an end of thebrush, the female quick-connect coupler comprising an outer sleeveslidable relative to an inner body, the outer sleeve being biased in adirection in which the brush is gripped within the female quick-connectcoupler, the female quick-connect coupler releasing the brush when theouter sleeve is urged in an opposite direction.

In some embodiments, for example, the shroud may comprise anobstruction, the obstruction being arranged to contact the outer sleeveof the female quick-connect coupler upon the brush connecting assemblybeing moved towards the aperture of the shroud thereby urging the outersleeve in the opposite direction and releasing the brush from the femalequick-connect coupler. As such, a brush would be automatically ejectedonce spent by simply continuing to actuate the adjustment sub-assembly.

In some embodiments, the electrolytic brush assembly of the presentinvention may have additional features in order to provide additionalfunctionality and advantages to those discussed above. For example, insome embodiments, the assembly may further comprise at least one sensor.The at least one sensor may be adapted to sense any one or moreparameters relevant to the operation of the electrolytic brush assembly.For example, the at least one sensor may sense a temperature of a brushconnected to the connecting assembly, an extent to which a brushconnected to the connecting assembly extends through the aperture of theshroud, and/or an amount of fumes contained in a volume defined by theshroud.

In embodiments of the present invention having such sensors, theassembly may further comprise means for adapting the assembly inresponse to the sensed conditions.

For example, in embodiments where the electrolytic brush assembly of thepresent invention comprises at least one sensor for sensing an extentthe brush extends through the aperture of the shroud, the assembly may,for example further comprise a driver for driving the actuator; and abrush drive controller for controlling the drive means based upon inputfrom the at least one sensor.

For example, in embodiments where the electrolytic brush assembly of thepresent invention comprises a sensor for sensing a temperature of abrush connected to the connecting assembly (the temperature of which isdependent on the wetness of the brush, which may not be visuallyobservable by the user), the assembly may, for example, further comprisea reservoir of cleaning fluid, a pump and conduits adapted to deliverthe cleaning fluid to the brush.

For example, in embodiments where the electrolytic brush assembly of thepresent invention comprises a sensor for sensing an amount of fumescontained in a volume defined by the shroud, the assembly may, forexample, further comprise conduit(s) and an extraction pump forextracting the fumes and disposing of them safely.

In some embodiments, the rate of delivery of electrolytic fluid to thebrush may be controlled in a closed loop manner such that the amount offluid in the brush is maintained at or near the optimum level. This maybe effected by varying the drive to the fluid pump or other fluidtransfer means in a manner that keeps a calculation derived from themagnitude of the signals received from sensing means at a constantlevel. Such sensing means may, variously, include a temperature sensorlocated in proximity to the brush, a signal proportional to the currentpassing through the brush and a signal proportional to the voltagemeasured across the brush. An additional sensing means may also measurethe instantaneous speed or volume flow of the fluid pump.

Specific embodiments of the present invention will now be describedbelow, by way of example only, with reference to the accompanyingdrawings. Where reference is made in any one or more of the accompanyingdrawings to features which have the same reference numerals, thosefeatures have for the purposes of this description the same function(s)or operation(s), unless the contrary intention appears.

FIG. 1 is a perspective view of an electrolytic brush assembly 100 inaccordance with an embodiment of the present invention. FIG. 2 is acut-away side view of the brush assembly 100 shown in FIG. 1. FIG. 3 isa detailed view of the brush 110 of the brush assembly 100 shown inFIGS. 1 and 2.

The brush assembly 100 is used for cleaning metals. More particularly,the brush assembly has a brush 110 having conductive filaments 111 whichare electrically charged. The brush assembly 100 is used in conjunctionwith an electrolyte (not illustrated) to clean a metal surface byapplying a concurrent chemical reaction, heat and electric current.

The brush assembly 100 has a handle assembly 150 for gripping an end 112of the brush 110 and conduct electrical current to the filaments 111 ofthe brush 110.

The handle assembly has a pistol grip handle 150. A distal end of thehandle 150 is equipped with an electrical connection 152 for receivingan electrical cable 153. The inside of the handle 150 is electricallyconductive for contacting electrical current to the remainder of thebrush assembly 100 as appropriate, while the outside surface of thehandle is insulated, allowing the brush assembly 100 to be handled.

The handle assembly also has a brush connecting assembly in the form ofa gripping sub-assembly 120 for griping the end 112 of the brush 110.The operation of the gripping sub-assembly 120 is described in detailbelow.

The handle assembly further has a shroud 140 from which the filaments111 of the brush 110 extends. The shroud 140 has an aperture 142 whichcontrols the shape of the filaments 111 extending therefrom and preventsthe filaments 111 from splaying out during use. The shroud 140 also hasventing holes 144 along the length thereof. The venting holes 144 allowhot fluid and steam to exit the shroud 140 during operation. The shroud140 is fixed relative to the non-moving parts of the handle assembly.Accordingly, the aperture 142 has a fixed position relative to thenon-moving parts, and more particularly, relative to the pistol griphandle 150.

Referring to FIG. 2, the handle assembly further has an adjustmentsub-assembly 130 for selectively moving the gripping sub-assembly 120,and thus the brush 110 gripped therein, towards and away from theaperture 142 of the shroud 140. Operation of the adjustment sub-assembly130 thus controls the effective length of the filaments 111 extendingfrom the aperture 142 of the shroud 140. Also, the adjustmentsub-assembly 130 may be used to replenish the effective length of thefilaments 111 extending from the aperture 142 as the distal ends of thefilaments 111 are depleted with use.

The adjustment sub-assembly 130 includes an inner rod 132 slidablyreceived within a sheath 134. The sheath 134 is also fixed relative tothe non-moving parts of the handle assembly, and is electricallyconnected to the conductive parts of the handle 150. The sheath 134 isfurther electrically connected to the rod 132 through a sliding contact135. Thus, electrical current is able to flow from the handle 150,through the sheath 134, to the rod 132 via the sliding contact 135, tothe gripping sub-assembly 120 and finally to the brush 110, and moreparticularly to the filaments 111 of the brush 110.

The rod 132 has a pin 138 extending therefrom, through a slot 139provided in the sheath 134. The slot 139 prevents the rod 132 fromrotating within the sheath 134, thereby restricting the movement of therod 132 relative to the sheath to linear movement only. The rod 132 ismechanically and electrically connected to the gripping sub-assembly120.

The adjustment sub-assembly 130 further includes a rotatable sleeve 136rotatable relative to the non-moving parts of the handle assembly. Therotatable sleeve 136 is insulated with respect to the voltage of thesheath 134 and typically rotated by hand. The rotatable sleeve 136 has ascrew thread 137 on the inner surface thereof. The thread 137 engagesthe pin 138 of the rod 132. When the rotatable sleeve 136 rotates, thehelical structure of the thread 137 converts the rotation of therotatable sleeve 136 into linear movement of the rod 132 relative to thesheath 134. Dependent upon the direction of the rotation of therotatable sleeve 136, the rod 132 and the connected brush 110 are movedtowards or away from the aperture 142 of the shroud 140.

Having described the operation of the adjustment sub-assembly 130, theoperation of the gripping sub-assembly 120 is now described in detail.The gripping sub-assembly 120 consists mainly of a female quick-connectcoupler for receiving the end 112 of the brush 110. The femalequick-connect coupler includes an outer sleeve 122 slidable relative tothe inner body of the coupler. The sleeve 122 is biased towards thereceiving end of the coupler by a spring 124. The inner body of thecoupler includes balls 126. The balls 126 are urged towards a centreaxis of the coupler when the sleeve 122 is in the rest position towardsthe receiving end of the coupler. While the sleeve 122 is slid againstthe bias of the spring 124, the balls 126 are free to move away from theaxis of the coupler.

Referring also to FIG. 3, the brush 110 has a recess 115 which, when thebrush 110 is received in the coupler, the balls 126 move into, and areretained in, the recess 115 when the sleeve 122 is slid by the spring124 towards the receiving end of the coupler, thereby locking the brush110 in place.

Referring to FIG. 2, the shroud 140 includes an obstruction in the formof a ridge 146. When the adjustment sub-assembly 130 is used to move thegripping sub-assembly 120 towards the aperture 142 of the shroud 140, atsome point the sleeve 122 of the coupler of the gripping sub-assembly120 contacts the ridge 146 of the shroud 140. Movement of the grippingsub-assembly 120 beyond this point towards the aperture 142 causes theridge 146 to urge against the sleeve 122, sliding the sleeve 122 awayfrom the receiving end of the coupler and against the bias of the spring122, thus releasing the balls 126. With the balls 126 released, theballs 126 are no longer forced into the recess 115 of the brush 110, andthe brush 110 is released from the gripping sub-assembly 120.

After removal of the brush 110, a replacement brush 110 may be fitted,after which the adjustment sub-assembly 130 is used to move the grippingsub-assembly 120 away from the aperture 142 of the shroud 140, and thusaway from the ridge 146 of the shroud 140. The bias of the spring 124causes the sleeve 122 to slide towards the receiving end of the coupler,thus forcing the balls 126 into the recess 115 of the replacement brush110, thereby locking the replacement brush 110 in place.

The end 112 of the brush 110 has a conical frustum shape, and thegripping sub-assembly 120 has a complementary shape, thereby ensuringeffective electrical contact between the gripping sub-assembly 120 andthe brush 110.

The end 112 of the brush 110 also has an entrance 116 to a passage (notillustrated) extending through the brush 110 towards the filaments 111.The end 112 also has an “o”-ring 118 which seals with the grippingsub-assembly 120 when the brush is gripped therein.

The shroud 140 may be fluidly connected through conduits (notillustrated) in the handle assembly to an external extraction pump,allowing fumes created during operation to be extracted.

The electrolytic brush assembly 100 described herein is particularlysuitable for use in an automatic electrolytic cleaning application. Theelectrolytic brush assembly 100 may be further provided with sensors(not illustrated) for sensing the length of the filaments 111 protrudingfrom the aperture 142 of the shroud 140. An electric stepper motor (notillustrated) is also provided for rotating the outer sleeve 136 tothereby further extend the filaments 111 through the aperture 142. Acontroller (not illustrated) may control the electric stepper motorbased upon input from the sensor i.e. the length of the filaments 111protruding from the aperture 142.

Referring to FIGS. 6 and 7, electrolytic fluid may be supplied to thebrush through the distal end 303 of fluid delivery tube (300) under theclosed loop control of a fluid pump (not shown). The rate of fluiddelivery is a function of input signals from, typically, sourcescomprising, a temperature sensing infra-red photo diode (301) located inproximity with the brush (not shown), a voltage level proportional tothe current measured passing through the brush (not shown) and a voltagelevel proportional to the voltage drop across the brush (not shown) viaconduit entry 302. Typically, the calculation used to relate the inputsignals to the fluid pump drive act to maintain the temperature of thebrush between two set limits, typically 120 and 300 deg C., and tomaintain the power dissipated in the brush between two set limits,typically 250 and 800 W. In this embodiment the power would becalculated as the product of the current passing through the brush andthe voltage across the brush.

Additionally, the fluid control means described above may alsoincorporate a function that reverses the fluid pump on switch off. Inconjunction with an anti syphon mechanism attached to the fluidreservoir this ensures that fluid does not leak out when the system isinactive. On switch on, the functionality is reversed whereby the fluiddelivery tube is automatically primed with fluid for instant delivery.

Referring now to FIGS. 4 and 5, an alternative form of a brushconnecting assembly in the form of gripping sub-assembly 200 is shown.Gripping sub-assembly 200 is adapted to be received within a shroud(e.g. shroud 140) and attached to the handle assembly (e.g. rod 132) ofan electrolytic brush assembly (e.g. electrolytic brush assembly 100).As described below, gripping sub-assembly 200 is particularly adapted togrip a cylindrically shaped brush (not shown), but would also be capableof gripping tapered brushes such as bush 110 (albeit less securely).

Gripping sub-assembly 200 includes a hollow tube 202 having a number ofdeformable portions with tapered ridges shown generally at 204, a pin206, a cylindrical sleeve 208, a spring 210 and an end cap 212. As canbe seen in FIG. 5, during assembly, the sleeve 208 is slid over thehollow tube 202 until it abuts the ridges of deformable portions 204,where it is prevented from travelling any further. Spring 210 is thenslid over the hollow tube 202 and inside of the sleeve 208, until itabuts flange 214 inside of the sleeve 208. End cap 212 is then slid overthe hollow tube 202 until the opposite end of the spring is containedtherein. End cap 212 can be moved towards sleeve 208 simply bycompressing the spring 210. Once assembled, the pin 206 is passedthrough hollow tube 202 in the manner shown in FIG. 5 so that all of thecomponents are retained on the hollow tube.

In use, forcing the sleeve 208 towards the end cap 212 (i.e. against thebias of spring 210) moves the sleeve off the ridges of deformableportions 204. Deformable portions 204 are therefore able to be spreadapart slightly, for example in order to receive an appropriately shapedcylindrical portion of a brush (not shown). Inserting the brush into theopen end 216 of the hollow tube 202 can be achieved whilst the sleeve208 has been forced towards the end cap 212. However, once such a forceis released, the bias of the spring 210 pushes the sleeve 208 back ontothe ridges of deformable portions 204 such that deformable portions 204are compressed together and thus securely retain the brush therebetween.

Hollow tube 202 is formed from an electrically conducting material suchthat, once retained therein, a current supplied to the hollow tube 202(e.g. via the rod 132, as discussed above) is passed into the bush (notshown) and its filaments.

Operation of the gripping sub-assembly 200 in an electrolytic brushassembly such as electrolytic brush assembly 100 may be similar to thatdescribed above with respect to gripping sub assembly 120. Inparticular, it is noted that ridge 146 could be adapted to force thesleeve 208 towards the end cap 212 (i.e. against the bias of spring 210)in order for the gripping sub-assembly to automatically be able to ejecta spent brush (i.e. once the adjustment sub-assembly has pushed thegripping sub assembly that far).

The inventors have found that the arrangement described above can resultin an electrical connection between the brush and the electrolytic brushassembly that is less prone to developing hot spots and build-up ofcarbon over time, resulting in a more consistent electrical connectiontherebetween. The arrangement is also a screw less fitting, meaning thatthe brush does not need to be rotated in order for it to be insertedinto the gripping sub-assembly 200, which can damage the filaments ofthe brush during insertion and necessitate that a user handle the(contaminated) spent brush during its removal.

The foregoing describes only some embodiments of the present invention,and modifications and/or changes can be made thereto without departingfrom the scope and spirit of the invention, the embodiments beingillustrative and not restrictive.

In the claims which follow and in the preceding description of theinvention, except where the context requires otherwise due to expresslanguage or necessary implication, the word “comprise” or variationssuch as “comprises” or “comprising” is used in an inclusive sense, i.e.to specify the presence of the stated features but not to preclude thepresence or addition of further features in various embodiments of theinvention.

It is to be understood that any prior art publication referred to hereindoes not constitute an admission that the publication forms part of thecommon general knowledge in the art.

1. An electrolytic brush assembly comprising: a handle assembly; ashroud extending from the handle assembly, the shroud having an apertureat a distal end thereof; a brush connecting assembly for releasablyconnecting a brush to the handle assembly whereby the brush extendsthrough the aperture of the shroud, wherein the handle assemblycomprises an adjustment sub-assembly for selectively moving the brushconnecting assembly and a brush connected thereto relative to the handleassembly and the aperture of the shroud; and an electrolytic fluiddelivery assembly whereby electrolytic fluid from an external source orreservoir is delivered to the proximity of an electrolytic brush by apressure source wherein the electrolytic fluid delivery system furthercomprises a fluid controller whereby the volume flow of electrolyticfluid may be varied automatically by the fluid controller in response toone or more measured input conditions.
 2. An electrolytic brush assemblyaccording to claim 1 wherein the adjustment sub-assembly comprises: asheath; a rod slidably received within the sheath, the rod beingconnected to the brush connecting assembly; an actuator for moving therod within the sheath, thereby moving the brush connecting assembly anda brush connected thereto relative to the handle assembly and theaperture of the shroud; and an electrolytic fluid delivery assemblywhereby electrolytic fluid from an external source or reservoir is bedelivered to the proximity of an electrolytic brush by the pressuresource.
 3. An electrolytic brush assembly according to claim 2 whereinthe actuator comprises a rotatable sleeve having an inner threadfunctionally connected to the rod, whereby rotation of the rotatablesleeve causes linear movement of the rod within the sheath, therebymoving the brush connecting assembly and a brush connected theretorelative to the handle assembly and the aperture of the shroud.
 4. Anelectrolytic brush assembly according to claim 1 wherein the brush isreleasably connectable to the brush connecting assembly by a quickrelease mechanism comprising a female quick-connect coupler forreceiving an end of the brush, the female quick-connect couplercomprising an outer-sleeve slidable relative to an inner body, the outersleeve being biased in a direction in which the brush is gripped withinthe female quick-connect coupler, the female quick-connect couplerreleasing the brush when the outer sleeve is urged in an oppositedirection.
 5. (canceled)
 6. An electrolytic brush assembly according toclaim 4 wherein the quick release mechanism shroud comprises anobstruction, the obstruction being arranged to contact the outer sleeveof the female quick-connect coupler upon the brush connecting assemblybeing moved towards the aperture of the shroud thereby urging the outersleeve in the opposite direction and releasing thy brush from the femalequick-connect coupler.
 7. An electrolytic brush assembly according toclaim 1 wherein the handle assembly further comprises a pistol griphandle.
 8. An electrolytic brush assembly according to claim 1 wherein abrush connected to the connecting assembly is fluidly connected to thehandle assembly for receiving a fluid from the handle assembly, thefluid being deliverable to filaments of the brush during operation. 9.An electrolytic brush assembly according to claim 1 wherein a volumedefined by the shroud is fluidly connected to conduits in the handleassembly, wherein the conduits are fluidly connectable to an externalextraction pump, thereby allowing fumes created within the volume to beextracted during operation.
 10. An electrolytic brush assembly accordingto claim 1 further comprising at least one sensor to measure the inputconditions selected from: a temperature of a brush connected to theconnecting assembly, electric current flowing through the brush,electric voltage developed across the brush, pressure source flowparameter and operator input setting, an extent to which a brushconnected to the connecting assembly extends through the aperture of theshroud, an amount of fumes contained in a volume defined by the shroud.11. (canceled)
 12. An electrolytic brush assembly according to claim 1further comprising: at least one sensor for sensing an extent to which abrush connected to the brush connecting assembly extends through theaperture of the shroud; a driver for driving the actuator; and acontroller for controlling the drive means based upon input from the atleast one sensor.
 13. An electrolytic brush assembly according to claim10 wherein the volume flow of electrolytic fluid is determined by thereception from the at least one sensor of parameter values which varywith the quantity of electrolytic fluid in the brush.
 14. Anelectrolytic brush assembly according to claim 11 wherein the controllerincludes an anti-siphon module connected to the fluid reservoir.
 15. Anelectrolytic brush assembly according to claim 1 wherein the fluidcontroller varies the flow of electrolytic fluid in a manner that seeksto maintain constant a calculation derived from the value of one or moremeasured input conditions.
 16. (canceled)
 17. An electrolytic brushassembly according to claim 1 wherein the sense of the pressure derivedfrom the electrolytic fluid pressure source may be reversed prior toswitching off the assembly.
 18. An electrolytic brush assembly accordingto claim 1 wherein in response to switch on, the electrolytic fluidpressure source may pressurise the electrolytic fluid delivery systemfor a finite period.
 19. An electrolytic brush assembly comprising: ahandle assembly; a shroud extending from the handle assembly, the shroudhaving an aperture at a distal end thereof; a brush releasably connectedto the handle assembly and extending through the aperture of the shroud,wherein the handle assembly comprises an adjustment sub-assembly forselectively moving the brush relative to the handle assembly and theaperture of the shroud; and an electrolytic fluid delivery assemblywhereby electrolytic fluid from an external source is delivered via aconduit to the proximity of an electrolytic brush by a pressure sourcewherein the electrolytic fluid delivery system further comprises a fluidcontroller whereby the volume flow of electrolytic fluid may be variedautomatically by the fluid controller in response to one or moremeasured input conditions. 20-22. (canceled)